Ryan (surname)

In some cases it may be a shortened form of O'Ryan, which is an Anglicized adaptation of the Gaelic surname Ó Riain, meaning "descendant of Rian".

[1] It can also be a shortened form of Mulryan or O'Mulryan, which are derived from the Gaelic Ó Maoilriain, meaning "descendant of the follower of Rian".

[3] Some sources have suggested that it is related to the Old Irish word rían, meaning "water" or "ocean".

[4][5] Others have suggested that it is related to the Old Irish word rí, meaning "king".

"[3] Popular modern sources typically suggest that Ryan means "little king"[8][9] or "illustrious".